Engine driven chain saw



p 1952 E. c. KIEKHAEFER 2,61 57 ENGINE DRIVEN CHAIN SAW Filed Oct. 7, 1948 1 3 Sheets-Sheet l mm 1 )PM Sept. 16, 1952 E. c. KIEKHAEFER ENGINE DRIVEN CHAIN SAW 3 Sheets-Sheet 2 Filed Oct. 7, 1948 IIIIIIIII/ll/l/l INVENTOR. 6722a," jz iekm/ r Sept. 16, 1952 E. c. KIEKHAEFER ENGINE DRIVEN CHAIN SAW 3 Sheets-Sheet 3 Filed Oct. 7, 1948 m zjw 7/l/arne1/s Patented Sept. 16, 1952 UNITED STATES PATENT' OFFICE I eivcme nmveNcmnvs-AW Elmer. 0,.Klekhhefer, camber-awn? v stoneware-norm,ism-semi net's-.201-

t-olaiins. (c1. ma -32) This invention relates to'engi'ne driven chain saws and particularly to the 'ni'anual' System of controls for such saws.

A principal object of the invention is to provide for the greater safety of the operator or the-sew and reduce the possibility of accidental injury, by providing engine and clutch controls which are more simple and easily operated.

Another object is to more iullyyassurethe complete safety of the operatorhypioviding engine and clutch controls which are instantly accessible. p 7 I Another object is to provide for the fulla'nd complete ease of control of the chainsaw in any cutting position.

Another object is to provide for the use of the saw in any cutting position'witliout changing the grasp of the control handle from one hand to the other. I v

Another object is to p'rovidea flngertipcom trol of the engine speed which-is not' exposed' to accidental disadjustment and isno'netheless easily accessible inan'y cutting position.

Another object is to provide for the" disengage:

ment of the clutch of the chain saw unites in.

the event that the operator has lost control-jot the saw, by contact of the clutch controli'with any part of the operator's l'iody.

These and other objects and advantages. of the invention will be more fuilyset forth in-the following description of a preferred embodiment:

Fig. 4 is a view'similar to showing-the.

handle locked in the position oi." clutch-disengage ment and with'the throttle at slowspeed:

Fig. 5 is an enlarged detailsection-ofthecliitch taken axially oi the engine crankshaft and tiie sprocket shaft showing the sprocketengaged-ior operation of the unit;

Fig. 6 is a perspective view of the'jchazin'saw a,

unit generally from one side and as supported upon a flat surface; and I Fig. '7 is a side view-oi the chainsawunit show ing the side oppositethatofr'im ti'iand with the longitudinal axis of the guide railextending horizontally and the abutment member engaging a log shown in dotted lines.

The chain saw'unit hown in the drawings comprises the engine i, the not guide rail 2 extending forwardly of theiinit and secured to scribed byithe gear '9 which meshes with the pinion It. Pinion it i'sfcrmed within-the-engine crankshaft-1i of engine *i between bearings 12 carrying oneend of the crankshaft. The gear a is mounted to rotateinthe bearing l3 within transmission easel shalt 8 is io'urnally' mount ed withintran'smission case 3 by the hearing it near the end carryingsprocket 1 and' is' carried atfthe'opposi'te' end bythe needle bearing 15 within-gear 9 to vrotate freely with" respect to the latter: The clutch element 16 which provides a positive drive connection between-shaft 8 and gear 9' comprises a circular member having c air of bosses" onthe side adjacent gear 9.: Element 16 is secured on shaft 8 for rotation therewith-by means ofthe splines lsj which allow axiai'amovenient or element Hi relative to shaft 8 and thexsel'eotive engagement and disengage ment of the bosses ll' 'with'-gear 9 within the recesses I 9 in theoppositeside of the gear.

The spring 20" within shaft tisdisposed between the phig'fl at theout'er-end or smart a and the crosstpinnfearried by-element it within slots 23 "of shaft 8 and extending through the shaft. spring -zii-nomaiiy-biases pin 22 and clutch element-it iii-one direction for en gagement with-gear 9'. The pushpins 24 and 25 are-disposed withinshaft 8 and at the side of pin-22 opposite spring jiiand' are adaptedto be engaged hythe-oamte to push-the pin 22 and element .it-in: the cpposite-directionjo itoi engagement with gear 9. Preferably pins 24- and ii-are oi hrass 'and steel respectively to provide sui tablev hearing surraces upon relative rotationalv movement. The shaft" 21 carries cam 26: adjacent theend of shaft 8 for engagement with the-end .of pin 25 projecting, from the end otshatt 8'."

Thes'piing-fl mounted on shaft 21 biases the sluttand: cam-I6 rotationally normally. to allow- 5 x engagement otol'utchreiement i6 and gear 9.

The lever 29 on the outer end of shaft 21 is connected to means under the control of the operator as will be described to effect selectively the rotation of shaft 21 against the biasing of spring 28 and of cam 26 thereby moving pin 22 within shaft 8 and the clutch element It in and out of engagement with gear 9.

The chain saw unit is adapted to be operated by one man and to be disposed with rail 2 in either horizontal or vertical positions of operation for cutting. In operation, chain 4 is driven at high speed on rail 2 and moves on the lower side of rail 2 toward the engine and operator holding the unit. The cutting is intended normally to be done by that portion of the chain on the lower side of rail 2. The horn projects downwardly at the end of rail 2 secured to engine I and is adapted to be engaged by the timber through which the chain is moving and cutting to carry the thrust of the unit normally in a direction away from the operator. The rail 2 extending forwardly of the unit is set at one side of the unit to allow cutting close to the ground without obstruction.

The tubular handle 3I secured to engine I extends freely over and downwardly on opposite sides of the chain saw unit and is secured to the engine beneath the unit to be grasped at the side uppermost with either the right or left hand of the operator in either of the two horizontal or vertical cutting positions. Handle 3I is located with respect to the center of gravity of the unit so that in operation the support of the saw is provided almostentirely by handle 3] allowing for manipulation of the unit and control of engine I by means ofa second control handle as will be described. The arrangement of handle 3I provides 'for the easy carrying and transporting of the saw in a normal balanced position. The rubber sheath 32 on handle 3I provides for easier gripping of the handle without slipping.

The control handle 33 secured to engine I on the rear side, opposite guide rail 2, comprises a single cast or stamped member. Handle 33 having a suitable opening 34 is of the pistol grip" type which is shaped to conform to the full grasp of the hand and is disposed centrally at the rear of the chain saw unit to be grasped with either the right or left hand. I f

The'clutch control 35 comprises preferably a stamped member of U-section disposed on the back side of handle 33 and which is pivotally secured thereto at the upper end' of the handle. Control member 35 is dimensioned to conform generally to the shape of the hand and is adapted to be squeezed or pressed forwardly over handle 33 with the palm of the hand grasping the handle.

The control rod 36 connected to the lower end of control member 35 extends beneath handle 33 and forwardly of the unit and is operativ'ely cone nected to the clutch lever 29 to control the driving connection of engine I and the saw chain 4. The rod 36 connects control member 35 and lever 29 so that when clutch control member. 35 is pressed forwardly as with the palm of-the hand against the biasing of springs 28 and 20, the clutch element I6 and gear 9 are disengaged and the chain. is operatively disconnected from the engine.

The latch 31 pivotally mounted within control member 35 near the lower end thereof is biasedby the spring 38 to engage the abutment 39 in the lower end of handle 33 when control member 35 is pressed forwardly, securing the member against movement and the clutch in disengagement. The sliding thumb piece 40 .at the .upper end of member '35 is connected'by the rod, 4|

4 therein to latch 31. Thumb piece 40 is disposed to be slidably moved upwardly with the thumb of the hand grasping handle 3| to disengage latch 3'! allowing spring 28 to move member 35 rearwardly efiecting engagement of clutch element i6 and gear 9.

The throttle lever 42 pivotally mounted at the upper end and forwardly of handle 33 within opening '34 is biased forwardly by the spring 43 and is adapted to be engaged with the index finger of the hand grasping handle 33. The gear segment 44 rotating with lever 42 engages the pinion 45 on shaft 46 which is connected to shaft 4I-of carburetor 5 to control the engine fuel sup leased and accelerates as the lever is moved rearwardly against spring 43.

The throttle lock 48 pivotally mounted on handle 33 is provided with a pin 49 adapted to be moved downwardly into engagement with pinion 45 in one direction and secure the same against rotation in the opposite direction and throttle lever 42 in the selected position ofadjustment. Look 48 operates so that when depressed against the biasing of the spring 50, the pin 49 moves into and is secured in locking engagement with pinion 25, and by pressing lever 42 rotating pinion 45 against the biasing of spring 43.-pin.49 is released to allowfurther adjustment of the carburetor. I a

The electrical push button switch 5I recessed in the top of handle- 33 is connected by the wire 6 to the ignition system to stop the engine upon depressing of the switch. a

The lever 53 conveniently provided at one side (tn? handle 33 controls the carburetor fuel mixure.

The recoil hand starter 54 is provided at the side of the unit at the end of-engine I opposite transmission case 3. Starter 54 is actuated by manual pulling of handle 55 upwardly and rearwardly of the unit while the latter is supported on members 3I and 35 and one hand of the operator grasps the top of handle 3I'above the unit to hold the same.

When operating the chain saw unit in either of the upright, inverted or either horizontal position, the clutch and carburetor'controls and ignition switch are disposed relative .to handle 33 within easy reach of the hand .and fingers grasping the handle.

In the event that the operator should lose control of the saw the clutch can be instantly disengaged by pressing member 35 with the arm or leg to stopthe chain. :Control member 35.is disposed immediately infront of the operator at all times and can be operated with the knee as'when, in certain instances, the saw unitlis. held with both hands grasping the tubular. handle 3i.

Handle 33 is disposed so that-the..saw can be easily held properly against the thrust of the chain and with the horn 30 against the. timber being cut. In the event thatthetimber should bind the upper part of the chain causing the saw suddenly to move out of thekerf toward the operator, control member 35. willusually be automatically pressed by thehand grasping handle 3| to automatically move and maintain the clutch elements in disengagement.

The control handle is intended to be used by both right and left handed persons. The simlicity of the control systexnmakes it easy for both right and left handed persons to learn and acquire quickly the necessary- "feelf of the saw. The control of the -saw.is the same in any cutting anions? position so that no unfamiliarityis experienced on the part of the less skilled operator when cutting in diffieulti'positions. The arrangement of the handles lessens fatigue on the part of the operator thereby further reducing the possibility of accidental injury. I I I The motion necessary to disengage the clutch in case of emergency is the same forall positions and becomes quickly a reflex action on the part of the operator. r

The arrangement of therhandles further allows the saw chainto be placed fully to one side with respect to the unit without unbalance of the unit in the hands .of the operator and enables the chain saw unit to be so designed for makingcuts close to the ground or other. obstructions without wastehil.

Various e" bodiments of the invention be employed withinv the scope .of the accompanying claims.

I claim:

1.111 a portable lightweight engine-driven chainsaw unit; having an engine, a saw chain disposed forwardly of the engine, and a clutch operatively connecting said engine and chain; a clutch control carried by and disposed rearwardly of the unit and oppositely of the chain respecting the unit, said clutch control comprising relatively movable members one of which is fixed to the unit and the other of which is connected to said clutch to actuate the same, said clutch being engaged when said members are separated and said clutch being disengaged when said members are closed together, said members being disposed to provide a single handle for manipulation of the unit with one hand and arranged to disengage the clutch when the members are moved to closed position upon a tight grasping of the members with the hand as in an emergency.

2. In a portable engine-driven chain saw unit haVing an engine, an endless saw chain extending forwardly of the unit, and a clutch operatively connecting said engine and said chain to drive the latter; control means for said unit comprising a fixed guide handle connected to and disposed rearwardly of the unit for manipulating the unit and a lever operatively connected to said clutch to control engagement and disengagement of the clutch and pivotally connected to the'unit and disposed rearwardly of the guide handle and adjacent thereto, said clutch being engaged when said lever is pivoted rearwardly away from said handle and being disengaged when said lever is pivoted forwardly toward said handle, and biasing means yieldably holding said lever in a rearward position for clutch engagement and operation. said lever being pressable forwardly respecting the unit and toward said handle to eifect immediate clutch disengagement as in the event of binding of the chain in the kerf causing move ment of the unit against the lever or by grasping said control means tightly in the hand.

3. In a portable engine-driven chain saw unit having an engine, a saw chain, a clutch operatively connecting said engine and said chain, and a chain guide rail rigidly secured to and extending forwardly of the unit; a grasping rail extending substantially around the unit at the center of gravity thereof and providing a series of hand holds for manually supporting the unit and the chain guide rail in any one of several cutting positions by either hand; control means for said unit comprising a fixed guide handle connected to and disposed rearwardly of the englne for manipulating the unit and a lever oper- 6: atively. connected tosaid. elutch to control. the same and pivotally connected to the-engine and disposed rearwardlyeof the guide handle and adjaeent thereto and rearwardlyof .thevunit so that in anyone of i the said cuttin'gpositions' the lever is operatively exposedfor'operation from the rear of -the:uni'tas-'b'y contactwith the operatoror a fixed object at the rear cit-the unit, said clutch being engaged when saidllever is pivoted rearwardly'away fromsaid handle andunit and being disengaged when said,-lever-is;pivoted forwardly toward said handle and unitpaspring vyieldably holding said lever in a rearward position for clutchen'gagement and operation, saidlever being pressable-,forwardlyjrespecting?the unit and toward said handle to: effect immediate ,clutch disengagement as in the event of rearward move,- mentaof, theunit or by grasping said control means tightly'in the hand,- and cooperating. latch means carried by said handle and lever and "disposed to securesaid lever inelutch disengaged position and releasable to" allow: movement of said lever for reengagement ofsaid clutch; v

4. -In combination with the structure of claim 3, wherein an engine control lever disposed adjacent to and forwardly of said fixed handle to be engaged by a finger of the hand grasping said handle in any one of said cutting positions.

5. In a one-man portable lightweight enginedriven chain saw unit, an engine having a transmission case, and a chain guide rail rigidly secured to said transmission case and extending forwardlyof the unit; a series of hand holds including a rail member extending circumferentially of the longitudinal axis of said guide rail and adjacent to the center of gravity of the unit, said member being secured at the bottom of the unit to I said transmission case and extending across the bottom of the unit and spaced from and alon the sides of the engine and secured thereto to protect the engine when accidently dropped, the upper of said series of hand holds being disposed transversely and above the unit with respect to said guide rail and adjacent the center of gravity of the unit, and rigid supporting means including a single guide handle connected to the unit rearwardly thereof oppositely of said guide rail, said series of hand holds and said guide handle means providing respectively for the major support of the unit with the guide rail disposed forwardly thereof in any of several cutting positions and the manipulation of the unit for advancing or withdrawal of the guide rail respecting the out, the lower parts of said rigid supporting means and said rail member extending beneath the unit to rigidly support the latter on the ground as for starting the engine and the like with the unit tilted rearwardly and the guide rail elevated from the ground to locate the upper hand hold vertically of and between the lower part of said rail member and said rigid supporting means, whereby the upper hand hold may be utilized to hold the unit steady upon the lower part of the rail member and supporting means when starting the engine as with a recoil starter.

6. In a lightweight, engine-driven portable chain saw unit adapted to be supported and operated by one man, and including an engine having a transmission case, a guide rail rigidly secured to the transmission case and extending forwardly of the unit, an endless cutting chain car- 7 mediate thereto, the lower portion of said chain being driven by the engine in a direction toward the abutment and the opposite portion or the chain being subject to binding by pinching thereof in the kert in which event the unit tends to be propelled by the engine in the direction of the operator and rearwardly of the unit; control means for the unit comprising a fixed guide handle connected to and disposed rearwardly of the unit and adjacent to the operator oppositely of the guide rail and chain, and handle means including a rail member secured to the unit and providing a series of hand holds extending circumterentially of the longitudinal axis of the guide rail and adjacent to the center of gravity or the unit, said handle means including a hand hold above the unit and substantially above and vertical of the abutment when the unit is upri ht for advancing the saw chain into a vertical cut pivotally about the portion of the abutment engaging the work, said handle means providing for the major support or the unit near the center of gravity thereof with the guide rail disposed forwardly in either the vertical or any of several cutting positions to allow the relatively free ma- 8 nipulation and control oi the unit by said control means.

MELMER C. KIEKHAEFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

